1. Field
The field relates to an organic light emitting display device, and more particularly to an organic light emitting display device capable of stabilizing the output of an external condition detection sensor.
2. Description of the Related Technology
In recent years, various flat panel displays have been developed. The flat panel displays are light-weight and small-sized, when compared to cathode ray tubes. Particularly, among the flat panel display devices, the organic light emitting display device is favored with excellent luminance and color purity. The organic light emitting display uses an organic compound as a light emitting material.
An organic light emitting display device is thin and light-weight and may be driven with low power consumption, and therefore it has been expected to be widely used in the field of portable display devices, etc.
However, a portable display device in which the organic light emitting display device is mounted may be exposed to various external environments. Therefore, the organic light emitting display device may have different visibilities according to the external conditions such as the intensity of ambient light, the ambient temperature, etc.
Therefore, it is necessary to adjust the output luminance of the organic light emitting display device according to the external conditions so as to provide visibility that is suitable for the user and prevent excessive light emission of the organic light emitting display.
For this purpose, an external condition detection sensor may be provided in the organic light emitting display device to output a detection signal by sensing the external conditions and control drive circuits according to the detection signal.
However, the output of the external condition detection sensor may be a small current signal. For example, when the external condition detection sensor is composed of a light detection sensor unit to correspond to the intensity of ambient light, a light detection sensor unit may output a light detection signal having a small current value.
Such an output of the external condition detection sensor is easily affected by noise from peripheral circuits or signal lines. Therefore, it is difficult to accurately adjust the output luminance of the organic light emitting display device to a reliable luminance level that corresponds to the external conditions because the output of the external condition detection sensor is unstable.